Edit, I missed the comment you made in the first post about un-clickable 3 dots which is an issue. Even if you were to copy the music to the drive, it doesn’t matter if Roon does not enable it as a storage location.
There was another setup with the same issue and it seemed logging out of the server and then back in, might have fixed things. Here is a link to that thread it might help.
[Previous post removed due to mis understanding]